3 comments

Let’s play a game. Suppose I can predict that next year the average temperature will be 1 degree higher.

Well how many ways can this be true? Consider a simple case where every day we shall produce an average temp. for the entire globe. Well one way it could be true is if every day of the year the temp is exactly one degree higher than the corresponding day in the previous year. Another way, though, is more extreme. Every day the average temp is exactly the same, except one day where it will be 365 degrees hotter than the previous corresponding day. The first case is probably the most mild of possibilities, the second case would be a global extinction event. You could get even more extreme, every day could be one degree cooler but one day which will be 730 degrees hotter! All these possibilities would vindicate a blanket prediction of ‘on average 1 degree warmer’.

Of course there isn’t just one temp each day of the year for the globe. There’s a different temp. each hour, each minute or more and different temps based on where you are on the globe and so on. So the number of ways a prediction of one degree could be true goes up even more.

So the number of ways a more specific prediction could be wrong while the general prediction could be right is huge. I could venture to predict that half the days will be one degree cooler and the other half of days will be two degrees hotter. Assuming my general prediction of 1 degree on average holds up, I could still be wrong in thousands of tiny specific predictions.

So with all of that whether or not a prediction of a specific glacier disappearing by a specific year is not really all that important (unless I was in the business of owning real estate just down hill from that glacier!) relative to the overall prediction(s) being closer to true.

Boonton,
Oddly enough, nobody is contesting that local temperature is the same as a global temperature. The IPCC made a prediction … which looks like it’s not turning out. Why do you have faith in their other predictions if they get these and other like it wrong?

Well actually global temperature is the sum of many local temperatures. A prediction of a 1% global increase has many possible ways of being right, but despite all the possible ways of being right, there are many ways it can be wrong. For example, if every single local temp. fell by 1% then the entire global temp. can’t rise by 1%.

But this doesn’t seem to be a prediction. First of all, it isn’t 2035. Second of all this seems to be a math error were 2350 in one report was miskeyed as 2035 in another leading to an alarming headline. (see http://news.bbc.co.uk/2/hi/8387737.stm). So what? A model that generates a 1 degree global temp increase prediction will also yield thousands of local predictions. Since there’s a huge number of ways to be right about a 1 degree global increase, odds are almost certain that even a highly accurate model will yield thousands of incorrect minor predictions. An easy way to dodge the issue and pretend there’s a serious problem with a model is to just focus on minor incorrect predictions while ignoring the larger picture.

That is what you did when I pointed out earlier that while air temps did not rise very quickly for a particular periods, sea temps did. Your assertion was ‘so what’….ignoring the big picture (the earth’s surface holding onto more thermal energy) while making hey out of lesser issues (getting the exact distribution of thermal energy between the seas, air and land exactly right).